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Biomedical subjects

R Zamir

Publications and source records attributed to R Zamir.

At least 37 records · Page 2Linked to original sources
PubMed1988

The significance of HLA studies in human-human hybridomas.

The technique of human-human (H + H) hybridoma is employed to generate human monoclonal antibodies. However, in contrast to mouse hybridomas, the human counterpart is very difficult to establish. It is still unclear what the precise reasons are for the failure to establish the human-human hybridoma technique as a routine. Analyses of HLA antigens of seven lymphocyte donors and 22 human cell lines generated by the H + H hybridoma technique have demonstrated the importance of the compatibility between human lymphocytes and the lymphoblastoid cell lines. Furthermore, there is a preferential expression of several HLA on human hybridomas (e.g. B51; B15; B18; B35). Screening several unrelated human lymphoblastoid cell lines available demonstrated preferred HLA antigens (A2, A3; A30/31; B5; B18; B15; B35), despite the fact that these lines were derived from subjects of different ethnic origins. It seems that HLA typing of donor lymphocytes and lymphoblastoid cell lines may help to increase the yield of H + H hybridomas.

Cell Fusion↗
PubMed1988

HLA antigens in patients with Heberden's nodes.

Tissue typing was performed on a group of 51 patients with Heberden's nodes (HN) (45 Ashkenazic and 6 non-Ashkenazic Jews). The frequency of HLA-DR2 was higher (P = 0.03) in the Ashkenazic patients than in the Ashkenazic controls. However, the association was not significant after correction for the number of tested alleles at that locus. In the second part of the study, HLA typing was performed on subjects from a family with multiple HN occurrences. Of the 13 family members typed, 9 had HN: 6 of these had the haplotype A2, Bw35, DR2. We conclude that the development of HN may be influenced by genetic factors. Our results may suggest an association between HN and HLA-DR2 in Ashkenazic Jews.

Female↗
PubMed1987

Human cholinesterase genes localized by hybridization to chromosomes 3 and 16.

A cloned human cDNA for cholinesterase (ChE) was used as a probe for in situ hybridization to spread lymphocyte chromosomes to map the structural human CHE genes to distinct chromosomal regions. The recent genetic linkage assignment of the CHE1 locus of the CHE gene to chromosome 3q was confirmed and further refined to 3q21-q26, close to the genes coding for transferrin (TF) and transferrin receptor (TFRC). The CHE1 allele localizes to a 3q region that is commonly mutated and then associated with abnormal megakaryocyte proliferation in acute myelodysplastic anomalies. In view of earlier findings that ChE inhibitors induce megakaryocytopoiesis in culture, this localization may indicate that ChEs are involved in regulating the differentiation of megakaryocytes. A second site for ChEcDNA hybridization was found on chromosome 16p11-q23, demonstrating that the CHE2 locus of the cholinesterase gene, which directs the production of the common C5 variant of serum ChE, also codes for a structural subunit of the enzyme and is localized on the same chromosome with the haptoglobin (HP) gene, both genes being found on the long arm of chromosome 16. The finding of two sites for ChEcDNA hybridization suggests that the two loci coding for human ChEs may include nonidentical sequences responsible for the biochemical differences between ChE variants.

Cholinesterases↗
PubMed1987

The polyglandular deficiency syndrome: a new variant in Persian Jews.

Five Persian Jews were detected with the polyglandular deficiency syndrome (PDS). Primary hypoparathyroidism and hypogonadism were present in each, adrenal insufficiency in two, and insulin-dependent diabetes mellitus and latent hypothyroidism in single subjects. The percentage of T and B cells, and the mononuclear cell response to phytohemagglutinin and Concanavalin A were normal in all five. IgG and IgA levels and the OKT4+/OKT8+ cell ratio were low in one subject. Antinuclear and antithyroid antibodies were present in one subject. HLA-DR5 was present in 4/4, HLA-24 and B5 (B51) in 3/4 subjects. A single case of isolated hypoparathyroidism (IHP) was detected among 12 first degree relatives. HLA antigens B8, DR3, were absent in all of these subjects. Seven non-Iranian Jews with IHP were also examined. HLA A26 or A25 were present in all seven. Persian Jews appear to have a unique variant of PDS.

Adolescent↗
PubMed1986

Familial lipoid adrenal hyperplasia: genetic marker data and an approach to prenatal diagnosis.

Some of the anatomic endocrine, and genetic aspects of lipoid adrenal hyperplasia were studied in an inbred Israeli-Arab family with two affected sibs. One sib, a genetic female, presented with acute Addisonian crisis. Endocrine studies documented elevated ACTH levels and no detectable steroids of gonadal or adrenal origin. The other patient, a male pseudo-hermaphrodite, was found at autopsy to have typical lipoid adrenal hyperplasia and ectopic adrenal tissue adjacent to an intra-abdominal testicle. Complete vagina, uterus, and fallopian tubes were present in addition to the Wolffian structures. This unique observation supports the view that steroids may be necessary for Müllerian inhibitory factor to induce regression of Müllerian structures. The segregation of 27 autosomal markers was studied in one affected and five unaffected sibs. Genetic linkage to HLA, MNS, and GPT is unlikely. In addition, the affected sib is heterozygote for a haplotype of chromosome 1 which includes the Rh, Fy, PGM-1 systems. Determination of fetal gender by the combined use of ultrasonography and amniocentesis is suggested for prenatal diagnosis and improved risk counselling.

Adrenal Hyperplasia, Congenital↗
PubMed1986

Male fertility in factor XIII deficiency.

Seven homozygotes for F-XIII deficiency were found in a large inbred Israeli-Arab kindred. One affected woman had early abortions. Two affected men and one probably affected man had children, two of whom also were affected. Paternity was confirmed by segregation of HLAs and erythrocyte antigens and enzymes. This is the first documentation of normal male fertility in unequivocally affected patients. Clinical variability or genetic heterogeneity may account for previously reported male infertility.

Consanguinity↗
PubMed1985

Human monoclonal anti-DNA antibodies react as lymphocytotoxic antibodies.

Two out of 25 monoclonal anti-DNA autoantibodies that were produced by human-human hybridoma were found to have lymphocytotoxic activity. The antibodies reacted with normal B and T lymphocytes at cold (4 degrees C) as well as at warm (37 degrees C) temperatures. The lymphocytotoxic activity of the monoclonal anti-DNA antibodies could be inhibited by prior incubation of the antibodies with either polynucleotides, e.g. poly(I), poly(dT) or anti-idiotypic antibodies, that had been raised against a dominant anti-DNA antibody. The cross-reactivity between nuclear material and lymphocyte membrane raises the question whether these apparently diverse materials have a shared epitope. The cross-reactivity between anti-DNA antibodies and lymphocyte membrane may account in part for the lymphopenia observed in systemic lupus erythematosus patients.

Antibodies, Monoclonal↗
PubMed1984

Familial cryoglobulinemia and C4 deficiency.

The coexistence of cryoglobulinemia and C4 deficiency was found in one family. Twelve subjects were examined, most of them being asymptomatic. Cryoglobulins were found in 9 members and its type was defined in 6 of them, 3 having mixed IgM-IgG and 3 having monoclonal IgM cryoglobulins. The concentration of the third component of the complement system was normal in 10 subjects, while the concentration of the fourth one was found to be below the lower limit of normal in 9 subjects. Only C4 deficiency--and not cryoglobulinemia--was HLA-linked. There was no evidence of HBs antigenemia. The results of this study are discussed in the light of the pertinent literature.

Complement C4↗
PubMed1984

HLA antigens A, B, C and DR in hay-fever families of similar environmental conditions.

Investigation of 98 members (healthy and affected) belonging to 17 hay-fever families, for clinical picture, total and specific IgE and HLA A, B, C and DR is presented. There was no significant correlation between hay-fever, total or specific IgE and a certain HLA antigen or haplotype. There was, however, an association between hay-fever and same haplotype within 4 of the 17 families.

Adult↗
PubMed1982

Late-onset type of 21-hydroxylase deficiency in childhood.

It was recently proposed that congenital and late-onset 21-hydroxylase deficiency are caused by two distinct recessive allelic genes. Although both genes are associated with the HLA system, only the late-onset type was found to be linked with the antigens B14 and DR1. Biochemical and immunological studies were conducted in two families with children suffering from 21-hydroxylase deficiency of postnatal onset. In the first family, of Jewish Ashkenazic origin, a 2 1/2-yr-old girl presenting with clitoromegaly was found to be homozygous for the antigens B14 and DR1. In the second family, of Arabic origin, all the children, their parents and a paternal aunt were clinically and/or biochemically affected, carrying the B14, but not the DR1 antigen on one or both HLA haplotypes. These data suggest that some cases of simple virilizing 21-hydroxylase deficiency in childhood are related to the late-onset type of 21-hydroxylase deficiency.

Adrenal Hyperplasia, Congenital↗
PubMed1981

HLA antigens in Jews with pemphigus vulgaris.

The association of HLA antigens with pemphigus in Jewish patients of various ethnic origins was investigated. Of 45 Ashkenazi patients, 31 (68.6%) had A26 (p less than 10(-5) and 32 (7175) had BW38 ( less than 10(-5)0. Among the 11 non-Ashkenazi patients, 7 (63.6%) had A26 and only 1 had BW38. The question whether the antigen A26 or BW38 is linked with the disease is discussed. Our findings may suggest that the primary association of pemphigus is with A26. This association may be stronger in Jewish male patients than in females. In view of the recent literature and our results it may be presumed that pemphigus in Jews is associated with antigens of Loci A and DR. No differences between pemphigus vulgaris and pemphigus erythematosus were observed.

Adult↗
PubMed1981

Familial systemic lupus erythematosus and C4 deficiency.

A heterozygous state for C4 deficiency was found in 14 members of a family with familial SLE. The HLA analysis in this family permitted us to re-establish the linkage assumed to exist between the gene (or genes) controlling the synthesis of the fourth component of the complement and the major histocompatibility complex. In addition, it was found that the complement deficiency is not necessarily associated with any serological or clinical abnormality. The heterozygous state for C4 deficiency can be added to the various serological abnormalities described in asymptomatic members of families with familial SLE. It is as yet unknown whether this deficiency may predispose to the subsequent development of SLE.

Adolescent↗
PubMed1980

Vitiligo and the HLA system.

77 Vitiligo patients were investigated for their HLA phenotype. Analysis of this material according to age of onset and ethnic origin revealed some significant characteristics. Young Jewish Moroccan patients showed a high frequency of B13 when compared to matching controls. Young patients of Yemenite origin had a strikingly high frequency of BW35. Jewish Yemenites showed a lack of B13 both in patients and in controls. It is suggested that studies by undertaken to clarify this problem further.

Age Factors↗